Estandarización de un ELISA para la cuantificación de anticuerpos IgG humanos contra células enteras de Bordetella pertussis / Standardization of an ELISA for the quantification of human IgG antibodies against whole cells of Bordetella pertussis

Bordetella pertussis es un patógeno exclusivo de humanos que causa la tos ferina, enfermedad respiratoria aguda que afecta principalmente a la población pediátrica. Existen dos tipos de vacunas comercializadas contra este patógeno: celulares y acelulares. Las vacunas celulares han sido extensamente utilizadas y siguen teniendo gran relevancia. El presente trabajo tuvo como objetivo la estandarización de un ELISA para la cuantificación de anticuerpos IgG contra células enteras de Bordetella pertussis. Para ello se determinó la concentración de recubrimiento, el rango lineal de la curva, los parámetros de precisión intra e interensayo, la especificidad, el valor de corte y el límite de detección. Se determinó como concentración de recubrimiento 0,5 UO/mL de células enteras. La curva estándar utilizando un suero de referencia internacional presentó un buen ajuste a una función polinómica en un intervalo entre las diluciones 1/100 y 1/24.300 con un coeficiente de correlación R2≥0,98. Los coeficientes de variación en los ensayos de precisión intra e interensayo estuvieron en los intervalos establecidos para cada uno (≤10 por ciento, ≤20 por ciento respectivamente). Los resultados obtenidos avalan el empleo de este ELISA cuantitativo para la evaluación de la respuesta a células enteras de Bordetella pertussis en ensayos clínicos(AU)

Bordetella pertussis is a pathogen exclusive to humans that causes pertussis, an acute respiratory disease that mainly affects the pediatric population. There are two types of vaccines commercially available against this pathogen: cellular and acellular. Cellular vaccines have been widely used and continue to be of great relevance. The aim of the present work was to standardize an ELISA for the quantification of IgG antibodies against whole cells of Bordetella pertussis. For this purpose, the coating concentration, the linear range of the curve, the intra- and inter-assay precision parameters, the specificity, the cut-off value and the detection limit were determined. The coating concentration was determined as 0.5 UO/mL of whole cells. The standard curve using an international reference serum presented a good fit to a polynomial function in a range between dilutions 1/100 and 1/24,300 with a correlation coefficient R2≥0.98. The coefficients of variation in the intra- and inter-assay precision tests were in the intervals established for each (≤10percent, ≤20percent respectively). The results obtained support the use of this quantitative ELISA for the evaluation of whole-cell response to Bordetella pertussis in clinical trials(AU)

Influence of the Co-Administration of Heptavalent Conjugate Vaccine PCV7-TT on the Immunological Response Elicited by VA-MENGOC-BC® and Heberpenta®-L in Rabbits.

Finlay Vaccine Institute is developing a new heptavalent conjugate vaccine against Streptococcus pneumoniae. As infants are the target population, PCV7-TT will be necessarily co-administered with other vaccines, and then, the interactions represent a concern. The aim of this work is to evaluate the possible immunological interferences in rabbits as animal experimental model. Rabbits were immunized with Heberpenta®-L, VA-MENGOC-BC®, and PCV7-TT. Blood samples were taken fourteen days after final immunization for obtaining sera. Antibody responses to all antigens were evaluated by indirect ELISA. Functional responses against diphtheria and tetanus toxoid were done by in vivo seroneutralization assay. No interference was observed by PCV7-TT over the humoral response against diphtheria toxoid and meningococcal antigens (p > 0.05). A nonstatistically significant reduction (p > 0.05) was observed in the case of the humoral response against Haemophilus influenzae type b oligosaccharide. Concomitant administration of Heberpenta®-L and PCV7-TT increased twice the antibody titers as well as the protective activity against tetanus toxoid, but no statistical differences were found. The co-administration did not induce a reduction in the percent of responders against pneumococcal polysaccharides contained in PCV7-TT vaccine. Concomitant administration of PCV7-TT did not induce interferences over the evaluated antigens of Heberpenta®-L and VA-MENGOC-BC®. Also, no interference was observed on the immune response elicited by PCV7-TT. These preclinical results suggest that PCV7-TT will not result in a serious problem over the immune response elicited by the licensed vaccines Heberpenta®-L and VA-MENGOC-BC®. However, the clinical interference could be strictly studied during clinical trials in infants.